president obama paid tribute to nelson mandela today. through his fierce dignity and unbending will to sacrifice his own freedom for the freedom of others i moved all of us. he embodied the promise that human beings and countries can change for the better. his commitment to transfer power and reconcile those who jailed him set an example for all to aspire to, whether in the lives of nations or in our own personal lives. >>> i promised you the president of the united states. and he's here. let's play "hardball." >> it's my honor to introduce the president of the united states. [ applause ] >> well, thank you, mr. president. >> it's good to see you. >> so what brought you to "hardball"? >> american university. [cheers and applause] >> "hardball" was just an excuse to hang out with these fine, young people. i've had just wonderful experiences here. first time i spoke here, actually, was when i was running for the presidency. and ted kennedy announced his endorsement here. obviously he was an incredible friend and spoke in here about immigra